The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Seattle you can figure out when you can plant gladiolus by checking out the USDA zone info.

Planting Calendar for Gladiolus

Frost tolerance for gladiolus:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant gladiolus slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant gladiolus in Seattle is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant gladiolus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your gladiolus may not have a chance to grow to maturity. If you are starting your gladiolus indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Seattle. You can expect an average low temperature of 15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Seattle is not always accurate and the actual date of last frost is different every year. Since half of the time in Seattle last frost occurs after March 15 be ready to protect your gladiolus in the event of one of those late frosts.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Seattle

You may be interested in your other planting guides for Seattle.